1、改变列标题：列标题=列名，列名 列标题
eg1:select 昵称=nickname,电邮=email from table
eg2: select nickname n,email e from table
2、改表名
alter table A rename to B
3、改列名new_name为my_name
eg: alter table student rename column new_name to my_name
4、改列数据类型
alter table student modify my_name int
5、改记录
update student set name='lfw' age=19 where id=2
6、改用户密码
alter user user1 identified by new_password
7、锁定用户
alter user user1 account lock
